G lass-ionomer cements, relatively new and promising materials, are presently advocated for clinical use as Class III and V restorative materials, fissure sealants, and cementing agents for castings.‘-7 The setting mechanism of the glass ionomers has been characterized by Crisp et al.*-lo The physical properties and resistance to solubility appear advantageous and this cement forms adhesive bonds to enamel, dentin, and treated platinum and gold.” I2 Additionally, fluoride leaches from the set cement to provide protection against caries, and animal studies have established pulpal compatibility.13-‘5 While all of these factors are extremely encouraging, the cementing effectiveness is not yet understood nor has it been properly documented. Recently, Chembond (L. D. Caulk Co., Milford, Del.), a material closely akin to the restorative material Aspa (Amalgamated Dental Co., London, England) but with reduced powder particle size, was offered for evaluation as an agent for cementing dental castings. The purpose of this study was to evaluate glass-ionomer cement as a potential luting agent, especially from a working-quality and effectiveness standpoint.